The world No. 1 is coming off not one, but two of the best seasons of her career. In 2013, she was more thorough than ever: Serena Williams won more matches (78) and more tournaments (11) than she had in any previous single year. Those 11 titles represent more than one-fifth of the 57 she has amassed during 15 seasons on tour.

Where can she go from here? Perhaps only Serena could say there’s room for improvement, and have those words ring true. While she has dominated consistently for the last 24 months, she hasn’t been quite as dominant at the events she cares about most, the Grand Slams. She “only”—her word—won two in 2012, and two again in 2013. While her game is better than ever, she has become more prone to anxiety on the big occasions. We’ll see which, her game or her nerves, triumphs, as she continues into her 30s.

Ad-In: With Serena, a calendar-year Grand Slam isn’t just a fantasy; if she’s confident, she should do it—she has no true rivals when she’s playing well. And she has won four straight before, in 2002-03, for her Serena Slam. To start, you know she wants the Aussie Open, which she hasn’t won since way back in 2010.

Ad-Out: It’s strange. Serena’s game has never been better, but her nerves may never have been shakier than they were in 2013. If she isn’t destroying an opponent, she can lose her cool. That may keep her from winning everything, but it’s almost impossible to imagine Serena not holding at least one major trophy. It would tie her on the all-time list with Chris Evert and Martina Navratilova.

As we approach the new year, we'll take a closer look at what's in store for the past year's top performers. To read more of our 2014 Season Previews, click here.